This invention relates to a switching regulator, and more particularly to a chopper type switching regulator which is able to operate with very low power consumption.
Recently, small-sized, high efficiency power sources have been used to provide low voltage and high current for semiconductor circuits, particularly integrated circuits. A switching regulator is especially useful in power sources for providing loads with stable DC power. Many efforts have been made to improve the efficiency of the switching regulator.
A switching regulator is known which utilizes an inductive kick from an inductor or a choke coil for smoothing the load current at a moment when current flowing through the choke coil has been cut off, and circulates the current produced by the inductive kick into a load as the load current. In a conventional switching regulator, the current circulation is affected by using a diode. The conventional switching regulator, however, has problems in that the power loss in the regulating circuit is relatively large because of the diode forward voltage drop of about 0.7 V (volt). The forward voltage drop is a problem for improving the power consumption efficiency in switching regulators, especially for small-sized equipments.
An example of the conventional switching regulator is shown in FIG. 1 and is discussed in connection with FIG. 2 below in the Description of the Preferred Embodiment.